Presentation on theme: "Lecture 3 Public Goods and Government intervention"— Presentation transcript:
1Lecture 3 Public Goods and Government intervention Suggested Readings: Connolly & Munro, The economics of the public sector, chapter 4
2Market failuresMarket failures occur when prices do not fully reflect either the marginal social benefits or costssuch failures provide scope for political interactionhow does this happen?Potential sources of market failurePublic Goods
3Public Goods Introduction In market economies, private suppliers provide the majority of goods and services to consumers. However, certain goods are publicly provided. These include for example defense, education, and health. Why does the government instead of the market provide these goods? Which characteristics differentiate goods that are privately provided from goods that are publicly provided? How do we define public goods?The terminology might induce the conclusion that public goods are good that are publicly provided as opposed to private goods. This conclusion is simply WRONG! The public or private nature of the good is an intrinsic characteristic of goods that is not related to the provider of the goodHence, it may well be that the state provides a private good or that the market provides a public good.
4Public Goods When is a good public? Definition: A pure public good is a good that has two characteristicsNON-EXCLUDABLENON-DEPLETABLE (NON-RIVAL, NO-CONGESTION)Non excludability: once the good is provided, it is not possible to prevent any individual (even individuals that eventually have not paid to access the good!) from using the good. The reason for non-excludability could be for example that is technically impossible to check who is using the good or that the cost of monitoring the use of the good is so high that “de facto” monitoring does not take placeNon-depletability (non rivalness): the fact that some people are using the good doesn’t not prevent other people from using the same good. In other words, the consumption by one person doesn’t reduce the quantity available for the consumption of other individualsWhen a good has these two characteristics, i.e. is non-excludable and non-depletable, then it is a pure public good. On the other hand, if a good is excludable and depletable, then the good is a private good. Finally, you have some good that possess just one of these properties.
6Public Goods Pure public goods: street light defense air radio emissions
7Public GoodsWhat are the implications of non-excludability and non-rivalness?Let’s compare a pure private good (X) and a pure public good (G)Suppose that X=1 and G=1Suppose there are two consumers: Anne and BillWho consumes X?Who consumes G?
8Public goods versus Private Goods Since X is excludable and rival, either Anne or Bill will consume it (it cannot be consumed by both!). Hence, the consumer that values the good the most (i.e. the consumer who is willing to pay the highest price) will consume X.With the public good this is not the case
9OPTIMAL PUBLIC GOOD PROVISION To provide optimally G, we need to take into account that G is simultaneously consumed by Anne and Bill, i.e. we need to take into account that each unit of G is going to increase the utility of both agents!Social Marginal Benefit as opposed to Private Marginal Benefit!
10Market Failure Can the market provide efficiently public goods? Private provision through voluntary contributionsexamples: charity, private securitynaively following own demand curves can lead to over or under provision
11Marginal benefit and demand curve for public goods Marginal CostMarginal cost15Optimal provision of Public good10No provision of public good1055Individual marginal benefitSocial marginal benefit107.57.510
12Strategic contributions contributors are not naïve – they observe and react to others’ behavior so act strategicallySuppose that the student union decides to buy a new big TV screen (let’s say to watch soccer or cricket!) and every member of the student union declares that he will really enjoy a new big screen!. To purchase the TV screen the union relies on the voluntary contributions of each member of the student union. Once the TV screen is bought, each member of the student union has access to the TV independently on the fact that he has contributed or not to the purchase of the TV.
13Strategic contributions The TV screen is in other words a public good for the members of the student union since it isnon-excludable (no member can be prevented from watching the TV)non-rival (the fact that one member watches the TV does not prevent other members from watching it)Question: assuming that you care about watching the next World Cup (or something better!) will you contribute to buy the TV screen?
14Strategic contributions Let’s give some numerical valuesSuppose that the cost of the TV is £100. Suppose that if two people contribute they will each pay $50. On the other hand if just one person contributes while the other refuses to pay, then she will pay the entire cost of £100. If nobody contributes, the TV is not bought. Let’s assume that the benefit for each individual from watching the TV in monetary terms is £75, on the other hand if the TV is not bought their payoff is just zero.Let’s write down the payoffs of the contribution game
16The free-rider problem This is an example of prisoner dilemma. The two individuals would clearly be better off contributing but they end up not contributing!Why do we obtain this result?This result is related to the public nature of the good. Because the good is non-excludable and non-rival, there is a strategic interdependence in the contribution decision of the two players.Loosely speaking, consider what individual 1 is thinking when he has to decide whether or not to buy the TVif he buys the TV, he cannot prevent individual 2 from using the TVif individual 2 buys the TV, he can use it for freeand similarly for individual 2!Hence, although each individuals enjoys having the TV, since each would enjoy it much more to use it for free, then they end up having no TV!This is known as the free-rider problem
17The free-rider problem The essence of the free-rider problem is that the contribution by one player is an exact substitute for the contribution of the other player. Therefore, each player tries to exploit the contribution from the other in order to obtain the good for free. As each player is reasoning in the same way, the result is that none of the players will voluntary contribute!In this example, where the quantity of the good is discrete (either the good is provided or it is not provided), if we rely on voluntary provision the good is not provided. In general, if we consider a continuos case, then the outcome will be that a sub-optimal quantity of public good is provided. It can also be shown that the free-riding problem becomes more severe as the number of players increases
18The free-rider problem To overcome the free rider problem, co-operation or co-ordination of society is required.Obstacle one – enforcement is needed to implement this behaviorrepeated interaction with tit-for-tat punishmentsgovernment activity or centralized decision making such as compulsory taxation or regulation
19WelfareWe have learned that when a good is public, because of strategic interdependence, the quantity of the public good provided by voluntary contributions is not Pareto-efficient.This is equivalent to say that if we rely on the market to provide the good, then the outcome is not efficient.This is an example of market failureIs there a way to solve the market failure?
20Government Intervention The government considers the utility of all the individuals in the society “jointly”, chooses the level of public goods that maximises the social surplus and introduces a tax to finance the public good.Therefore, if the government knows the preferences of each individual, he can provide efficiently the public goodThis is not particularly difficult if all individuals have the same preferences (for example, if you all enjoy in the same way watching the TV at the student union)
21Government Intervention However, individuals typically are heterogeneous in their preferences for goodsHow should the government choose the quantity of public good if individuals have different tastes?Suppose that g is the public good and c(g) is the cost of providing the public good. Let’s denote U1(g) the benefit for individual 1 from using g and U2(g) the benefit for of individual 2.
22The Samueson RuleThe social surplus is the sum of the utilities of the two individuals, minus the cost of provision of the good. The government has to decide the optimal level of g, that is the level of g that maximises the social surplus:Social surplus : U1(g)+U2(g)-C(g)the optimal g is reached when the marginal benefit is equal to the marginal cost. Note that, since we are not considering one individuals, but several, then the optimal g is reached when the sum of the marginal benefit of the individuals is equal to the marginal cost (Samuelson rule)U’1(g)+U’2(g)=C’(g)Samuelson rule: the optimal quantity of g is such that the sum of the marginal evaluation of the goods for the two individuals is equal to the marginal cost of the good.
23Samuelson Rule and Pareto frontier The social surplus maximising outcomes can be represented graphically using the Pareto-frontier (remember the frontier of UPS from last lecture).We can represent all the levels of net utilities that can be achieved choosing different levels of g.Every point on the frontier satisfies the Samuelson rule. Therefore, the Samuelson rule does not determine a precise outcome (doesn’t pick a specific point on the frontier).
25Mechanism of collective decision making How is a point on the frontier actually chosen?To choose a precise point we need to specify some type of collective choice ruleEx1: the government has some welfare function (i.e. a function that gives a precise weight to each individual in the society) and he chooses a point according to this welfare function. Then depending on the weight he gives to each individual, he can choose a different pointEx2: there is some political mechanism, like majority voting to decide
26Local public goods and the Tiebout Mechanism Individuals vote with their feetIf there are as many communities as there are types, then efficiency will resultArgument is related to club solutions to public goodsThis mechanism relaxes assumption somewhat on excludability
27Aggregation of preferences If there are not as many communities as types, individuals with different preferences have to find a way to undertake decisions affecting the entire groupGroup preferences and group choice
28Questions (prepare and answer all questions before next week seminar) Which one of the following goods is a pure public good?Health careRoadsEducationRadio emissionWirelessSuppose that Anne and Bill have agreed to buy a new dishwasher for their house. Bill values the dishwasher more than Anne and he would be willing to pay up to £300 pounds for a new dishwasher, while Anne is willing to spend up to £150. They finally agree to buy a dishwasher whose cost is £250. If both of them contribute, they will share equally equally the cost of £250. If one of them refuses to contribute, the other will pay the entire cost. If none of them contributes they will not buy the dishwasher. Will Anne contribute? Does your answer change if we assume that Anne and Bill both are willing to pay up to £160 for the dishwasher? Explain whether the Nash equilibrium in both cases is Pareto-efficient and discuss whether a compulsory contribution scheme would be welfare improving.